# phet moving man sim lab

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PhET Moving Man and Maze Game Simulations Lab
Investigating motion; distance, velocity, and acceleration through time

Introduction:
Distance and speed are scalar quantities; they are shown only with a magnitude. Displacement, velocity and
acceleration are vector quantities; in addition to their magnitude they also have a direction. For instance, the
velocity vector of your car as you drive down the road can be imagined as a large arrow that a points forward
(like your headlights) and grows as you increase speed.

Procedure:
Find the PhET simulations on the desktop. When you load a sim, read the instructions for that sim and          . Click “No”
if prompted to save. Note: these sims can be run from home (http://phet.colorado.edu) but you may have to update Java on
your computer. You can type exact values into the magnitude boxes                      .

Part I: The Moving Man (          the graphs between runs) Turn on the vectors                    .
Take five minutes to play; move the man with your mouse and observe the three graphs. Set some values. Have fun.
1.   Set the man’s velocity to 5 m/s and              . Try it again with v = -5 m/s.
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2. Set the man’s acceleration to 5 m/s .            . Try it again with a = -5 m/s.
3. Set the man’s velocity to 5 m/s and acceleration to 5 m/s2. Try it again with v = -5m/s and a = -5m/s2.
4. Set the man’s velocity to +5 m/s and acceleration to -5 m/s2. Try it again with v = -5m/s and a = +5m/s2.
5. Remove the walls (special features free range)
Setup this scenario:
1. A car traveling 5m/s slams on its brakes, creating an acceleration of -2 m/s2. How far did the car travel after it applied
its brakes? __________
2. The same car traveling for 10m/s applies the same acceleration of -2 m/s2. How far did the car travel after it applied
its brakes? __________
Another scenario:
1. The house is 8 meters away from the man. Only pressing             once, get the man to start at 0 and stop at the
house. (hint: don’t use position) DON’T HELP THE LAZY KIDS CHEAT!
Some Formulas:
1. The formula for displacement with a constant velocity is Δx = vt. Confirm this by setting acceleration =0, choosing a
velocity, and then          -ing and           -ing the simulation at various times.
2.   The formula for displacement with a constant acceleration is Δx = ½ at2. Confirm this by setting v =0 and choosing
an acceleration.

Part II: The Maze Game (you’ll need a mouse pad or sturdy piece of paper/cardboard)
Play the game, first controlling position, then velocity, then acceleration. After each person in your group has completed and
checked off Practice and Level 1, attempt Level 2.                                  (Who’s the winner? ______________ )
Practice P    V     A      Level 1 P     V       A                 Level 2 P       V       A         CD P       V      A

Conclusion Questions
1. When velocity and acceleration have the same sign, the object is not moving / speeding up / slowing down .(circle)
2. When velocity and acceleration have the opposite sign, the object is not moving / speeding up / slowing down.
3. Consider the braking car. When the speed was doubled, the distance to a stop was less than double / double / more
than double.
4. So…if it takes me 10 meters to stop while traveling 60 mph on the freeway, if I travel 75mph (20% faster) I should
expect to stop in less than 12 meters / 12 meters / much more than 12 meters.
5. To get the man to stop at home, I set the velocity to __________ and acceleration to __________.
6. If velocity was 3 m/s, then the displacement = ____ after 2 seconds, ____ after 3 seconds, and ____ after 5 seconds.
7. If acceleration was 2 m/s2, then the displacement = ____ after 2 seconds, ____ after 4 seconds.
8. When the formulas for displacement (above) are added, the resulting formula would be Δx =____________________.
9. If an object experiences a velocity of 3 m/s and a constant acceleration of 2 m/s2, then the distance it traveled after 2
seconds would be __________ and after 3 seconds it traveled___________. (feel free to test it)

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 views: 159 posted: 2/10/2012 language: English pages: 1